A lawyer for investment fund Hermitage Capital Management, jailed on tax charges related to his work for the fund, has died in custody, Irina Dudukina, spokeswoman for the Investigative Committee of Russia’s Interior Ministry said Tuesday.

She provided no further details, saying a release would be issued later. Sergei Magnitsky and his colleagues had accused authorities of denying him necessary medical treatment in prison.

Mr. Magnitsky, a 37-year-old partner at Moscow firm Firestone Duncan, was jailed nearly a year ago on charges of tax evasion related to his work for Hermitage. At a court hearing on extending his detention in September, he complained that he had been denied medical treatment for weeks for serious stomach pancreatic illnesses that he hadn’t suffered from before his imprisonment. He also complained of inhumane conditions — including the absence of toilet, hot water and windows — at the Butyrskaya jail where he was then being held.

“They held him for 11 months, asking him to fabricate testimony against Hermitage,” said Jamison Firestone, managing partner of Firestone Duncan. “The more he refused, the worse his conditions became.”

If convicted of tax fraud, Mr. Magnitsky would have faced up to six years in prison. Russian officials have denied pressuring Mr. Magnitsky for testimony.

Hermitage, run by U.S.-born investor William Browder, denies the tax-evasion charges. The fund has accused officials of the Russian Interior Ministry of using documents and seals taken from Hermitage during a 2007 search to steal companies used by the fund and apply for $230 million in fraudulent tax refunds from the Russian government. The ministry denies those charges.

Mr. Browder was one of the best-known foreign investors in Russia, with a reputation for publicly crusading against waste and mismanagement at Russia state-controlled companies. But Russian authorities stripped him of his visa in 2005 on national-security grounds and he hasn’t been able to return since. The Interior Ministry says he’s been charged with tax evasion, allegations he denies.

Excerpts from the report, published by the Committee on Legal Affairs and Human Rights on allegations of politically-motivated abuses of the criminal justice system in Council of Europe member states with recommendations on series of steps to strengthen the independence of judges and prosecutors across Europe to end politically-motivated interference in individual cases.

Inter alia the Committee calls for a series of reforms to reduce the political and hierarchical pressures on judges and put an end to the harassment of defence lawyers in order to combat “legal nihilism” in the Russian Federation, as a precondition also for successful co-operation between Russian and other European law enforcement authorities.

A report approved today by the Legal Affairs Committee of the Council of Europe Parliamentary Assembly (PACE) has recommended a series of steps to boost the independence of judges across Europe to end what it calls “politically-motivated interference” in individual cases.

The report, prepared by Sabine Leutheusser-Schnarrenberger (Germany, ALDE), exposes ways that politicians can meddle with the law in four countries representing the principal types of criminal justice system in Europe, analysing high-profile cases such as the dropping of the BAE fraud investigation and “cash for honours” scandal in the United Kingdom, or the second Khodorkovsky trial, HSBC/Hermitage Capital case and Politkovskaya investigation in Russia.

Among other things, the parliamentarians call for:

• in Russia, a series of reforms to reduce the political pressures on judges and end the harassment of defence lawyers in order to combat “legal nihilism” in Russia.